Process for producing solid catalyst component and catalyst for alpha-olefin polymerization, and process for producing alpha-olefin polymer

ABSTRACT

There are disclosed a process for producing a solid catalyst component and a catalyst for α-olefin polymerization, and a process for producing an α-olefin polymer, wherein the process for producing a solid catalyst component comprises the steps of:  
     (1) reducing a specific titanium compound with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond (and an ester compound), thereby obtaining a solid product, and  
     (2) contacting the solid product with at least one member selected from the group consisting of an electron donor compound (E1) and an organic acid halide, and a compound having a Ti-halogen bond, thereby obtaining the solid catalyst component.

FIELD OF THE INVENTION

[0001] The present invention relates to a process for producing a solidcatalyst component for α-olefin polymerization, a process for producinga catalyst for α-olefin polymerization, and a process for producing anα-olefin polymer.

BACKGROUND OF THE INVENTION

[0002] As a catalyst for a high stereospecificity polymerization of anα-olefin, the following catalysts are known.

[0003] (1) A catalyst obtained by combining a support type solidcatalyst component prepared by supporting a tetravalent titanium halideon a magnesium halide with an organoaluminum compound as a co-catalystand an organosilicon compound as a third component (refer to JP-A57-63310, JP-A 58-83006 and JP-A 61-78803).

[0004] (2) A catalyst obtained by combining a trivalent titaniumcompound-containing solid catalyst component with an organoaluminumcompound as a co-catalyst and an electron donor compound as a thirdcomponent, wherein the trivalent titanium compound-containing solidcatalyst component is prepared by reducing a titanium compound with anorganomagnesium compound in the presence of both an organosiliconcompound and an ester compound to obtain a solid product, and treatingthe solid product with an ester compound, followed by successivetreatment with a mixture of an ether compound and titanium tetrachlorideor a mixture of an ether compound, titanium tetrachloride and an estercompound (refer to JP-A 7-216017).

[0005] (3) A catalyst obtained by combining a trivalent titaniumcompound-containing solid catalyst component with an organoaluminumcompound as a co-catalyst and an electron donor compound as a thirdcomponent, wherein the trivalent titanium compound-containing solidcatalyst component is prepared by reducing a titanium compound with anorganomagnesium compound in the presence of both an organosiliconcompound and an ester compound to obtain a solid product, and treatingthe solid product with a mixture of an ether compound and titaniumtetrachloride, followed by successive treatment with an organic acidhalide compound, and further followed by successive treatment with amixture of an ether compound and titanium tetrachloride or a mixture ofan ether compound, titanium tetrachloride and an ester compound (referto JP-A 10-212319).

[0006] However, an α-olefin polymer obtained by polymerization using anyof catalysts mentioned above does not have stereospecificity of asatisfactory level, from a viewpoint of the facts that (1) a moldedarticle having a higher rigidity is desired particularly in the field ofinjection molding, and (2) rigidity of an injection-molded article isincreased with increase in stereospecificity of a polymer to be used.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a process forproducing a catalyst for α-olefin polymerization, which catalyst has ahigh polymerization activity and a stereospecificity polymerizationability of a high level so that removal of an amorphous polymer is notneeded.

[0008] Another object of the present invention is to provide a processfor producing a solid catalyst component used for the production of sucha catalyst.

[0009] A further object of the present invention is to provide a processfor producing an α-olefin polymer by using such a catalyst.

[0010] The present invention provides a process for producing a solidcatalyst component (1) for α-olefin polymerization, which comprises thesteps of:

[0011] (1) reducing a titanium compound represented by the followingformula [I] with an organomagnesium compound in the presence of anorganosilicon compound having an Si—O bond, thereby obtaining a solidproduct, and

[0012] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining the solid catalyst component (1) for α-olefinpolymerization,

[0013] wherein “a” is a number of 2 to 20, R² is a hydrocarbon grouphaving 1 to 20 carbon atoms, and X² is a halogen atom or ahydrocarbyloxy group having 1 to 20 carbon atoms, and all of X² may bethe same or different from one another.

[0014] The present invention also provides a process for producing asolid catalyst component (2) for α-olefin polymerization, whichcomprises the steps of:

[0015] (1) reducing a titanium compound represented by the above formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond and an ester compound, thereby obtaining asolid product, and

[0016] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining the solid catalyst component (2) for α-olefinpolymerization.

[0017] The present invention further provides a process for producing acatalyst (1) for α-olefin polymerization, which comprises the steps of:

[0018] (1) reducing a titanium compound represented by the above formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond, thereby obtaining a solid product,

[0019] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (1) for α-olefinpolymerization, and

[0020] (3) contacting the solid catalyst component (1), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining the catalyst (1) for α-olefin polymerization.

[0021] The present invention still further provides a process forproducing a catalyst (2) for α-olefin polymerization, which comprisesthe steps of:

[0022] (1) reducing a titanium compound represented by the above formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond and an ester compound, thereby obtaining asolid product,

[0023] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (2) for α-olefinpolymerization, and

[0024] (3) contacting the solid catalyst component (2), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining the catalyst (2) for α-olefin polymerization.

[0025] The present invention additionally provides a process forproducing an α-olefin polymer, which comprises the steps of:

[0026] (1) reducing a titanium compound represented by the above formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond compound, thereby obtaining a solidproduct,

[0027] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (1) for α-olefinpolymerization,

[0028] (3) contacting the solid catalyst component (1), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining a catalyst (1) for α-olefin polymerization,and

[0029] (4) subjecting an α-olefin to homopolymerization orcopolymerization in the presence of the catalyst (1).

[0030] The present invention still additionally provides a process forproducing an α-olefin polymer, which comprises the steps of:

[0031] (1) reducing a titanium compound represented by the above formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond and an ester compound, thereby obtaining asolid product,

[0032] (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (2) for α-olefinpolymerization,

[0033] (3) contacting the solid catalyst component (2), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining a catalyst (2) for α-olefin polymerization,and

[0034] (4) subjecting an α-olefin to homopolymerization orcopolymerization in the presence of the catalyst (2).

[0035] In the present invention, the solid catalyst components (1) and(2) for α-olefin polymerization are hereinafter together referred to as“solid catalyst component” for brevity, and the catalysts (1) and (2)for α-olefin polymerization are also hereinafter together referred to as“catalyst” for brevity.

DETAILED DESCRIPTION OF THE INVENTION

[0036] Electron Donor Compound (E1)

[0037] Examples of the electron donor compound (E1) used for theproduction of the solid catalyst component in accordance with thepresent invention are oxygen-containing compounds such as ethers(containing diethers), ketones, aldehydes, carboxylic acids, organicacid esters, inorganic acid esters, organic acid amides, inorganic acidamides and acid anhydrides; and nitrogen-containing compounds such asammonia, amines, nitriles and isocyanates. Of these, organic acid estersand ethers are preferred, carboxylic acid esters and diethers are morepreferred, and carboxylic acid esters are most preferred.

[0038] As the carboxylic acid esters, for example, mono-carboxylic acidesters and poly-carboxylic acid esters are enumerated. Morespecifically, saturated aliphatic carboxylic acid esters, unsaturatedaliphatic carboxylic acid esters, alicyclic carboxylic acid esters andaromatic carboxylic acid esters are enumerated.

[0039] Specific examples of the carboxylic acid esters are methylacetate, ethyl acetate, phenyl acetate, methyl propionate, ethylpropionate, ethyl butyrate, ethyl valerate, ethyl acrylate, methylmethacrylate, ethyl benzoate, butyl benzoate, methyl toluate, ethyltoluate, ethyl anisate, diethyl succinate, dibutyl succinate, diethylmalonate, dibutyl malonate, dimethyl maleate, dibutyl maleate, diethylitaconate, dibutyl itaconate, monoethyl phthalate, dimethyl phthalate,methyl ethyl phthalate, diethyl phthalate, di-n-propyl phthalate,di-i-propyl phthalate, di-n-butyl phthalate, di-i-butyl phthalate,di-n-octyl phthalate and diphenyl phthalate.

[0040] Among these carboxylic acid esters, unsaturated aliphaticcarboxylic acid esters such as methacrylic acid esters and maleic acidesters, and aromatic carboxylic acid esters such as benzoic acid estersand phthalic acid esters are preferred, and aromatic polycarboxylic acidesters are particularly preferred. Of these, dialkyl phthalates are mostpreferred.

[0041] Preferred diethers are those represented by the followingformula,

[0042] wherein R⁵ to R⁸ are independently of one another a straight- orbranched-chain or alicyclic alkyl group having 1 to 20 carbon atoms; anaryl group; or an aralkyl group, provided that R⁶ and R⁷ may beindependently of each other a hydrogen atom.

[0043] Specific examples of the diethers are2,2-di-i-butyl-1,3-dimethoxypropane,2-i-propyl-2-i-pentyl-1,3-dimethoxypropane,2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,2-i-propyl-2-3,7-dimethyloctyl-1,3-dimethoxypropane,2,2-di-i-propyl-1,3-dimethoxypropane,2-i-propyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2,2-dicyclohexyl-1,3-dimethoxypropane,2-i-propyl-2-i-butyl-1,3-dimethoxypropane,2,2-di-i-propyl-1,3-dimethoxypropane,2,2-di-propyl-1,3-dimethoxypropane,2-i-propyl-2-cyclohexyl-1,3-dimethoxypropane,2-i-propyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-di-cyclopentyl-1,3-dimethoxypropane and2-heptyl-2-pentyl-1,3-dimethoxypropane.

[0044] Among diethers represented by the above formula, preferreddiethers are those having the alkyl group as R⁵ to R⁸ which areindependent of each other, and more preferred are those having thebranched-chain or alicyclic alkyl group as R⁶ and R⁷ which areindependent of each other, and the 58 straight-chain alkyl group as R⁵and R⁸ which are independent of each other.

[0045] Organic Acid Halide

[0046] A preferred organic acid halide used in the present invention ismono- or poly-carboxylic acid halides. As the organic acid halides, forexample, aliphatic carboxylic acid halides, alicyclic carboxylic acidhalides and aromatic carboxylic acid halides are enumerated. Specificexamples of the organic acid halides are acetyl chloride, propionicchloride, butyric chloride, valeric chloride, acrylic chloride,methacrylic chloride, benzoic chloride, toluic chloride, anisicchloride, succinic chloride, malonic chloride, maleic chloride, itaconicchloride and phthalic chloride. Of these, aromatic carboxylic acidchlorides such as benzoic chloride, toluic chloride and phthalicchloride are preferred. Aromatic dicarboxylic acid dichlorides are morepreferred, and phthalic chloride is particularly preferred.

[0047] Compound having a Ti-halogen Bond

[0048] A preferred compound having a Ti-halogen bond used in the presentinvention is a titanium compound represented by the following formula,

Ti(OR⁹)_(b)X⁴ _(4−b)

[0049] wherein R⁹ is a hydrocarbon group having 1 to 20 carbon atoms, X⁴is a halogen atom, and b is a number satisfying 0≦b<4.

[0050] Examples of R⁹ are alkyl groups such as methyl, ethyl, propyl,i-propyl, butyl, i-butyl, tert-butyl, amyl, i-amyl, tert-amyl, hexyl,heptyl, octyl, decyl and dodecyl groups; aryl groups such as phenyl,cresyl, xylyl and naphthyl groups; allyl group; and aralkyl groups suchas a benzyl group. Among these R⁹, alkyl groups having 2 to 18 carbonatoms and aryl groups having 6 to 18 carbon atoms are preferred, andstraight-chain alkyl groups having 2 to 18 carbon atoms are particularlypreferred. As the compound represented by the above formula, it isallowed to use those having two or more OR⁹ groups different from oneanother.

[0051] As X⁴ in the above formula, a chlorine atom, a bromine atom andan iodine atom are exemplified. Of these, a chlorine atom isparticularly preferred.

[0052] A preferred b in the above formula is a number satisfying 0≦b≦2,and a particularly preferred b is 0.

[0053] Specific examples of the titanium compound represented by theabove formula are titanium tetrahalides such as titanium tetrachloride,titanium tetrabromide and titanium tetraiodide; hydrocarbyloxytitaniumtrihalides such as methoxytitanium trichloride, ethoxytitaniumtrichloride, butoxytitanium trichloride, phenoxytitanium trichloride,and ethoxytitanium tribromide; and dihydrocarbyloxytitanium dihalidessuch as dimethoxytitanium dichloride, diethoxytitanium dichloride,dibutoxytitanium dichloride, diphenoxytitanium dichloride, anddiethoxytitanium dibromide. Among these titanium compounds, the mostpreferred is titanium tetrachloride.

[0054] Organosilicon Compound having an Si—O Bond

[0055] Preferable examples of the organosilicon compound having an Si—Obond are, for example, those represented by any one of the followingformulas,

Si(OR¹⁰)_(t)R¹¹ _(4−t),

R¹²(R¹³ ₂SiO)_(u)SiR¹⁴ ₃ and

(R¹⁵ ₂SiO)_(v)

[0056] wherein R¹⁰ is a hydrocarbon group having 1 to 20 carbon atoms,R¹¹, R¹², R¹³, R¹⁴ and R¹⁵ are independently of one another ahydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, t is anumber satisfying 0<t≦4, u is an integer of from 1 to 1000, and v is aninteger of from 2 to 1000.

[0057] Specific examples of the organosilicon compound aretetramethoxysilane, dimethyldimethoxysilane, tetraethoxysilane,triethoxyethylsilane, diethoxydiethylsilane, ethoxytriethylsilane,tetra-i-propoxysilane, di-i-propoxy-di-i-propylsilane,tetrapropoxysilane, dipropoxydipropylsilane, tetrabutoxysilane,dibutoxydibutylsilane, dicyclopentoxydiethylsilane,diethoxydiphenylsilane, cyclohexyloxytrimethylsilane,phenoxytrimethylsilane, tetraphenoxysilane, triethoxyphenylsilane,hexamethyldisiloxane, hexaethyldisiloxane, hexapropyldisiloxane,octaethyltrisiloxane, dimethyl polysiloxane, diphenyl polysiloxane,methylhydro polysiloxane and phenylhydro polysiloxane.

[0058] Among these, more preferable are alkoxysilane compoundsrepresented by the formula Si(OR¹⁰)_(t)R¹¹ _(4−t), wherein t ispreferably a number satisfying 1≦b≦4. Of these, tetraalkoxysilanecompounds of t=4 are particularly preferred, and the most preferred istetraethoxysilane.

[0059] Titanium Compound

[0060] Examples of R² in the above formula [I] representing the titaniumcompound used in the present invention are alkyl groups such as methyl,ethyl, propyl, i-propyl, butyl, i-butyl, amyl, i-amyl, hexyl, heptyl,octyl, decyl and dodecyl groups; aryl groups such as phenyl, cresyl,xylyl and naphthyl groups: cycloalkyl groups such as cyclohexyl andcyclopentyl groups; allyl groups such as a propenyl group; and aralkylgroups such as a benzyl group. Among these, alkyl groups having 2 to 18carbon atoms and aryl groups having 6 to 18 carbon atoms are preferred,and straight-chain alkyl groups having 2 to 18 carbon atoms areparticularly preferred.

[0061] As the halogen atom represented by X² in the above formula [I], achlorine atom, a bromine atom and an iodine atom are exemplified. Ofthese, a chlorine atom is particularly preferred. As the oxyhydrocarbongroups having 1 to 20 carbon atoms represented by X² in the aboveformula [I], an alkoxy group having a straight-chain alkyl group of 2 to18 carbon atoms is particularly preferred. A preferred “a” in the aboveformula [I] is a number satisfying 2≦a≦5, and a more preferred “a” is 2or 4.

[0062] As specific examples of the titanium compound, tetra-i-propylpolytitanate (a mixture of compounds of “a”=2˜10), tetra-n-butylpolytitanate (a mixture of compounds of “a”=2˜10), tetra-n-hexylpolytitanate (a mixture of compounds of “a”=2˜10) and tetra-n-octylpolytitanate (a mixture of compounds of “a”=2˜10) are exemplified. Assuch a compound, a condensate of a tetraalkoxytitanium obtained byreacting a tetralkoxytitanium with a small amount of water is furtherexemplified. Of these, tetra-n-butyl polytitanate is more preferred, andtetra-n-butyltitanium dimer or tetra-n-butyltitanium tetramer isparticularly preferred.

[0063] It is permitted to use the titanium compound mentioned above incombination with a titanium compound represented by the followingformula,

Ti(OR²)_(q)X³ _(4−q)

[0064] wherein R² is a hydrocarbon group having 1 to 20 carbon atoms, X³is a halogen atom, and q is a number satisfying 0<q≦4.

[0065] Organomagnesium Compound

[0066] The “organomagnesium compound” used in the present inventionmeans any types of organomagnesium compounds having a magnesium-carbonbond. As the organomagnesium compound, a Grignard compound representedby the following first formula, and a dihydrocarbyl magnesium compoundrepresented by the following second formula are particularly suitable.

R¹⁶MgX⁵

[0067] In this formula, Mg is a magnesium atom, R¹⁶ is a hydrocarbongroup having 1 to 20 carbon atoms and X⁵ is a halogen atom.

R¹⁷R¹⁸Mg

[0068] In this formula, Mg is a magnesium atom, R¹⁷ and R¹⁸ areindependently of each other a hydrocarbon group having 1 to 20 carbonatoms.

[0069] In the above second formula, R¹⁷and R¹⁸ may be the same ordifferent from each other. Specific examples of R¹⁶ to R¹⁸ are alkyl,aryl, aralkyl and alkenyl groups having I to 20 carbon atoms such asmethyl, ethyl, propyl, i-propyl, butyl, sec-butyl, tert-butyl, i-amyl,hexyl, octyl, 2-ethylhexyl, phenyl and benzyl groups. It is particularlyrecommendable to use the Grignard compound represented by the abovefirst formula in the form of an ether solution thereof from a viewpointof polymerization activity of the catalyst obtained.

[0070] It is permitted to use the organomagnesium compound incombination with an organometallic compound to form a hydrocarbonsoluble complex. Examples of the organometallic compounds are compoundsof Li, Be, B, Al and Zn.

[0071] Ester Compound

[0072] In the present invention, it is recommendable to use an estercompound from a viewpoint of improving a polymerization activity and astereospecificity polymerization ability of the catalyst obtained. The“ester compound” means a mono- or poly-carboxylic acid ester. As theester compound, for example, saturated aliphatic carboxylic acid esters,unsaturated aliphatic carboxylic acid esters, alicyclic carboxylic acidesters and aromatic carboxylic acid esters are enumerated. Specificexamples of the ester compounds are methyl acetate, ethyl acetate,phenyl acetate, methyl propionate, ethyl propionate, ethyl butyrate,ethyl valerate, methyl acrylate, ethyl acrylate, methyl methacrylate,ethyl benzoate, butyl benzoate, methyl toluate, ethyl toluate, ethylanisate, diethyl succinate, dibutyl succinate, diethyl malonate, dibutylmalonate, dimethyl maleate, dibutyl maleate, diethyl itaconate, dibutylitaconate, monoethyl phthalate, dimethyl phthalate, methyl ethylphthalate, diethyl phthalate, di-n-propyl phthalate, di-i-propylphthalate, di-n-butyl phthalate, di-i-butyl phthalate, di-n-octylphthalate and diphenyl phthalate.

[0073] Among these ester compounds, unsaturated aliphatic carboxylicacid esters such as methacrylic acid esters and maleic acid esters andaromatic carboxylic acid esters such as phthalic acid esters arepreferred. Dialkyl phthalates are particularly preferred.

[0074] Solid Product

[0075] The organosilicon compound, the titanium compound and the estercompound, which are used for the production of the solid product, arepreferably dissolved in or diluted with a suitable solvent, and thenused therefor. Examples of the solvent are aliphatic hydrocarbons suchas hexane, heptane, octane and decane; aromatic hydrocarbons such astoluene and xylene; alicyclic hydrocarbons such as cyclohexane,methylcyclohexane and decalin; and ether compounds such as diethylether, dibutyl ether, di-i-amyl ether and tetrahydrofuran.

[0076] A temperature of the reduction reaction is usually from −50 to70° C., preferably from −30 to 50° C., and particularly preferably from−25 to 35° C. A time required for the reduction reaction is notparticularly limited, and it is usually from about 30 minutes to about 6hours. After the reaction is carried out at the above-mentionedtemperature, it is permitted to further carry out a post-reaction at atemperature of from 20 to 120° C.

[0077] The reduction reaction may be carried out in the presence of aporous carrier such as inorganic oxides and organic polymers, wherebythe solid product produced can be supported on the porous carrier. Theporous carrier may be conventional ones. Examples of the porous carrierare porous inorganic oxides such as SiO₂, Al₂O₃, MgO, TiO₂ and ZrO₂; andorganic porous polymers such as polystyrene, styrene-divinylbenzenecopolymer, styrene-ethylene glycol-methyl dimethacrylate copolymer,polymethylacrylate, polyethylacrylate, methyl acrylate-divinylbenzenecopolymer, polymethylmethacrylate, methyl methacrylate-divinylbenzenecopolymer, polyacrylonitrile, acrylonitrile-divinylbenzene copolymer,polyvinyl chloride, polyethylene and polypropylene. Of these, organicporous polymers are preferred, and styrene-divinylbenzene copolymer andacrylonitrile-divinylbenzene copolymer are particularly preferred.

[0078] With respect to the porous carriers, (i) a volume of micro poreshaving a radius of from 200 to 2000 A is preferably 0.3 cc/g or more,and more preferably 0.4 cc/g or more, and (ii) a proportion of thevolume of micro pores having a radius of from 200 to 2000 Å ispreferably 35% or more, and more preferably 40% or more, provided that avolume of micro pores having a radius of from 35 to 75000 Å is assignedto be 100%. It is not recommendable to use a porous carrier having toosmall micro pore volume, because the catalyst component is not supportedon the carrier effectively. Meanwhile, even if a porous carrier has amicro pore volume of 0.3 cc/g or more, the catalyst component is notsupported on the carrier eeffectively when the porous carrier does notsatisfy its micro pore radius of from 200 to 2000 Å.

[0079] The organosilicon compound is used in an amount of usually from 1to 500, preferably from 1 to 300, and more preferably from 3 to 100 interms of an atomic ratio Si/Ti, i.e. a ratio of a silicon atom in theorganosilicon compound to a titanium atom in the titanium compound.

[0080] The organomagnesium compound is used in an amount of usually from0.1 to 10, preferably from 0.2 to 5.0, and more preferably from 0.5 to2.0 in terms of an atomic ratio (Ti+Si)/Mg, i.e. a ratio of the sum of atitanium atom in the titanium compound and a silicon atom in theorganosilicon compound to a magnesium atom in the organomagnesiumcompound.

[0081] Alternatively, it is permitted that respective amounts of thetitanium compound, the organosilicon compound and the organomagnesiumcompound are determined so as to make a molar ratio of Mg/Ti in thesolid catalyst component from 1 to 51, preferably from 2 to 31, and morepreferably from 4 to 26.

[0082] The ester compound is used in an amount of usually from 0.5 to100, preferably from 1 to 60, and more preferably from 2 to 30 in termsof a molar ratio, ester compound/Ti, i.e. a ratio of the ester compoundto a titanium atom in the titanium compound.

[0083] The solid product obtained by the reduction reaction is separatedusually by solid-liquid separation, and washed several times with aninert hydrocarbon solvent such as hexane and heptane. The thus obtainedsolid product contains a trivalent titanium atom, a magnesium atom and ahydrocarbyloxy group, and in general has an amorphous structure or anextremely low crystallinity. A solid product having the amorphousstructure is particularly preferred from a viewpoint of catalystperformance.

[0084] Solid Catalyst Component

[0085] In a process for obtaining the solid catalyst component bycontacting the above-mentioned solid product with at least one memberselected from the group consisting of the electron donor compound (E1)and the organic acid halide, and the compound having a Ti-halogen bond,all of respective contacts are usually carried out under atmosphere ofan inert gas such as nitrogen and argon.

[0086] Said contact can be carried out, for example, by the followingmethods (1) to (4), wherein each contact may be repeated several times.

[0087] (1) The solid product is contacted with at least one memberselected from the group consisting of the electron donor compound (E1)and the organic acid halide, followed by successive contact with thecompound having a Ti-halogen bond.

[0088] (2) The solid product is contacted with a mixture of at least onemember selected from the group consisting of the electron donor compound(E1) and the organic acid halide, and the compound having a Ti-halogenbond, followed by successive contact with the compound having aTi-halogen bond.

[0089] (3) The solid product is contacted with the compound having aTi-halogen bond, followed by successive contact with at least one memberselected from the group consisting of the electron donor compound (E1)and the organic acid halide.

[0090] (4) The solid product is contacted with the compound having aTi-halogen bond, followed by successive contact with at least one memberselected from the group consisting of the electron donor compound (E1)and the organic acid halide, and further followed by successive contactwith the compound having a Ti-halogen bond.

[0091] Preferred solid catalyst components are those obtained by thebelow mentioned processes (1) and (2). (1) A solid catalyst componentobtained by a process wherein the solid product is contacted with theelectron donor compound (E1), followed by successive contact with thecompound having a Ti-halogen bond.

[0092] (2) A solid catalyst component obtained by a process here in thesolid product is contacted with the compound having a Ti-halogen bondand the organic acid halide, followed by successive contact with theelectron donor compound (E1) and the compound having a Ti-halogen bond.

[0093] More preferred solid catalyst components are those obtained bythe below mentioned processes (1) to (6).

[0094] (1) A solid catalyst component obtained by a process wherein thesolid product is contacted with the electron donor compound (E1),followed by successive contact with the compound having a Ti-halogenbond.

[0095] (2) A solid catalyst component obtained by a process wherein thesolid product is contacted with the electron donor compound (E1),followed two times by successive contact with the compound having aTi-halogen bond.

[0096] (3) A solid catalyst component obtained by a process wherein thesolid product is contacted with the electron donor compound (E1),followed two times by successive contact with a mixture of the electrondonor compound (E1) and the compound having a Ti-halogen bond.

[0097] (4) A solid catalyst component obtained by a process wherein thesolid product is contacted with the compound having a Ti-halogen bondand the organic acid halide, followed by successive contact with thecompound having a Ti-halogen bond.

[0098] (5) A solid catalyst component obtained by a process wherein thesolid product is contacted with the compound having a Ti-halogen bondand the organic acid halide, followed three times by successive contactwith the compound having a Ti-halogen bond.

[0099] (6) A solid catalyst component obtained by a process wherein thesolid product is contacted with the electron donor compound (E1), thecompound having a Ti-halogen bond and the organic acid halide, followedthree times by successive contact with a mixture of the electron donorcompound (E1) and the compound having a Ti-halogen bond.

[0100] Particularly preferred solid catalyst components are thoseobtained by the below mentioned processes (1) to (3).

[0101] (1) A solid catalyst component obtained by a process wherein thesolid product is contacted with the electron donor compound (E1),followed two times by successive contact with a mixture of the electrondonor compound (E1) and the compound having a Ti-halogen bond.

[0102] (2) A solid catalyst component obtained by a process wherein thesolid product is contacted with a mixture of the electron donor compound(E1), the compound having a Ti-halogen bond and the organic acid halide,followed three times by successive contact with a mixture of theelectron donor compound (E1) and the compound having a Ti-halogen bond.

[0103] (3) A solid catalyst component obtained by a process wherein thesolid product is contacted with a mixture of the electron donor compound(E1) and the compound having a Ti-halogen bond, followed by successivecontact with the organic acid halide, and further followed three timesby successive contact with a mixture of the electron donor compound (E1)and the compound having a Ti-halogen bond.

[0104] The above-mentioned contact can be carried out by a conventionalmethod such as a slurry method and a mechanical pulverization methodusing a ball mill. However, the latter is not recommendable from anindustrial point of view, because a lot of fine powders may be producedto make a particle size distribution of the solid catalyst componentobtained broad. Therefore, it is recommendable to carry out the contactin the presence of a diluent mentioned below.

[0105] Respective solids obtained by the above-mentioned contacts can beused as they are for the successive contact. However, it isrecommendable to wash the solid with a diluent mentioned below, therebyremoving unnecessaries contained in the solid.

[0106] The diluent is preferably a compound inert to the materials to betreated. Examples thereof are aliphatic hydrocarbons such as pentane,hexane, heptane and octane; aromatic hydrocarbons such as benzene,toluene and xylene; alicyclic hydrocarbons such as cyclohexane andcyclopentane; and halogenated hydrocarbons such as 1,2-dichloroethaneand monochlorobenzene.

[0107] When the diluent is used during the above-mentioned contact, anamount of the diluent per contact is usually from 0.1 ml to 1000 ml, andpreferably from 1 ml to 100 ml per g of the solid product. When thediluent is used for the washing as mentioned above, an amount thereofper washing is similar to that in the contact. The washing is carriedout usually from 1 to 5 times per contact.

[0108] The contact and washing can be carried out usually at atemperature of from −50 to 15° C., preferably from 0 to 140° C., andmore preferably from 60 to 135° C. A time for the contact is notparticularly limited. It is preferably from 0.5 to 8 hours, and morepreferably from 1 to 6 hours. Also, a time for the washing is notparticularly limited. It is preferably from 1 to 120 minutes, and morepreferably from 2 to 60 minutes.

[0109] The electron donor compound (E1) is used in an amount of usuallyfrom 0.1 to 50 mol, preferably from 0.3 to 30 mol, and more preferablyfrom 0.5 to 20 mol per mol of the titanium atom in the solid product.When the amount is too large, destruction of the solid product mayoccur.

[0110] The organic acid halide is used in an amount of usually from 1 to500 mol, preferably from 3 to 200 mol, and more preferably from 5 to 100mol per mol of the titanium atom in the solid product, and usually from0.01 to 1.0 mol, and preferably from 0.03 to 0.5 mol per mol of themagnesium atom in the solid product. When the amount is too large,destruction of the solid product may occur.

[0111] The compound having a Ti-halogen bond is used in an amount ofusually from 10 to 10,000 mol, preferably from 30 to 5,000 mol, and morepreferably from 100 to 3,000 mol per mol of the titanium atom in thesolid product.

[0112] It is recommendable to use the compound having a Ti-halogen bondin combination with the electron donor compound (E1). In this case, thecompound having a Ti-halogen bond is used in an amount of usually from 1to 100 mol, preferably from 1.5 to 75 mol, and more preferably from 2 to50 mol per mol of the electron donor compound.

[0113] When each compound mentioned above is subjected to severalcontacts, the above-mentioned amount is that per contact.

[0114] Usually, the solid catalyst component obtained according to theprocesses mentioned above are separated by solid-liquid separation,successively washed several times with an inert hydrocarbon solvent suchas hexane and heptane, and then used for the polymerization. From aviewpoint of polymerization activity and stereospecificitypolymerization ability of the catalyst, it is recommendable that thesolid obtained by the solid-liquid separation is washed at a temperatureof 50 to 120° C. at least one time with a large amount of a halogenizedhydrocarbon solvent such as monochlorobenzene or an aromatic hydrocarbonsolvent such as toluene, successively washed several times with analiphatic hydrocarbon solvent such as hexane, and then used for thepolymerization.

[0115] Organoaluminum Compound

[0116] The “organoaluminum compound” used in the present invention meansa compound having at least one Al-carbon bond in the molecule. Typicalexamples thereof are those represented by the following formulas,

R¹⁹ _(w)AlY_(3−w) and

R²⁰R²¹Al—O—AlR²²R²³

[0117] wherein R¹⁹ to R²³ are independently of one another a hydrocarbongroup having 1 to 20 carbon atoms, Y is a halogen atom, a hydrogen atomor an alkoxy group, and w is a number satisfying 2≦w≦3.

[0118] Specific examples of said compound are trialkylaluminums such astriethylaluminum, tri-i-butylaluminum and trihexylaluminum;dialkylaluminum hydrides such as diethylaluminum hydride anddi-i-butylaluminum hydride; dialkylaluminum halides such asdiethylaluminum chloride; mixtures of trialkylaluminums anddialkylaluminum halides such as a mixture of triethylaluminum anddiethylaluminum chloride; and alkylalumoxanes such astetraethyldialumoxane and tetrabutyldialumoxane.

[0119] Among these, trialkylaluminums, mixtures of trialkylaluminums anddialkylaluminum halides and alkylalumoxanes are preferred.Triethylaluminum, tri-i-butylaluminum, a mixture of triethylaluminum anddiethylaluminum chloride, and tetraethyldialumoxane are particularlypreferred.

[0120] Electron Donor Compound (E2)

[0121] As the electron donor compound (E2) used in the presentinvention, for example, oxygen-containing electron donor compounds suchas ethers including diethers, ketones, aldehydes, carboxylic acids,organic acid esters, inorganic acid esters, organic acid amides,inorganic acid amides and acid anhydrides; and nitrogen-containingelectron donor compounds such as ammonia, amines, nitriles andisocyanates are enumerated. Of these, inorganic acid esters and diethersare preferred, and alkoxysilicon compunds represented by the followingformula are more preferred,

R³ _(r)Si(OR⁴)_(4−r)

[0122] wherein R³ is a hydrocarbon group having 1 to 20 carbon atoms ora hydrogen atom, R⁴ is a hydrocarbon atoms having 1 to 20 carbon atoms,and r is a number satisfying 0≦r<4. All of R3 and all of R⁴ are the sameor different from one another, respectively.

[0123] Particularly preferred electron donor compounds are alkoxysiliconcompounds represented by the following formula,

R²⁴R²⁵Si(OR²⁶)₂

[0124] wherein R²⁴ is a C_(3˜20) hydrocarbon group, whose carbon atomadjacent to Si is secondary or tertiary, R²⁵ is a C_(1˜20) hydrocarbongroup and R²⁶ is a C_(1˜20) hydrocarbon group.

[0125] As R²⁴, for example, branched chain alkyl groups such asisopropyl, sec-butyl, tert-butyl and tert-amyl groups; cycloalkyl groupssuch as cyclobutyl, cyclopentyl and cyclohexyl groups; cycloalkenylgroups such as a cyclopentenyl group; and aryl groups such as pheny andtolyl groups are enumerated. As R²⁵, for example, straight chain alkylgroups such as methyl, ethyl, propyl, butyl and pentyl groups, branchedchain alkyl groups such as isopropyl, sec-butyl, tert-butyl andtert-amyl groups; cycloalkyl groups such as cyclopentyl and cyclohexylgroups; cycloalkenyl groups such as a cyclopentenyl group; and arylgroups such as pheny and tolyl groups are enumerated. As R²⁶,hydrocarbon groups having 1 to 5 carbon atoms are preferred.

[0126] Specific examples of the alkoxysilicon compounds used as theelectron donor compound (E2) are di-i-propyldimethoxysilane,di-i-butyldimethoxysilane, di-tert-butyldimethoxysilane,tert-butylmethyldimethoxysilane, tert-butylethyldimethoxysilane,tert-butyl-n-ptropyldimethoxysilane, tert-butyl-n-butyldimethoxysilane,tert-amylmethyldimethoxysilane, tert-amylethyldimethoxysllane,tert-amyl-n-propyldimethoxysilane, tert-amyl-n-butyldimethoxysilane,i-butyl-i-propyl-dimethoxysilane, tert -butyl-i-propyldimethoxysilane,dicyclobutyldimethoxysilane, cyclobutyl-i-propyldimethoxysilane,cyclobutyl-i-butyldimethoxysilane, cyclobutyl-tert-butyldimethoxysilane,dicyclopentyldimethoxysilane, cyclopentyl-i-propyldimethoxysilane,cyclopentyl-i-butyldimethoxysilane,cyclopentyl-tert-butyldimethoxysilane, dicylohexyldimethoxysilane,cyclohexylmethyldmethoxysilane, cyclohexylethyldimriethoxysilane,cyclohexyl-i-propyldimethoxysilane, cyclohexyl-i-butyldimethoxysilane,cyclohexyl-tert-butyldimethoxysilane,cyclohexylcyclopentyldimethoxysilane, cyclohexylphenyldimethoxysilane,diphenyldimethoxysilane, phenymethyldimethoxysilane,phenyl-i-propyldimethoxysilane, phenyl-i-butyldimethoxysilane,phenyl-tert-butyldimethoxysilane, phenylcyclopentyldimethoxysilane,di-i-propyldiethoxysilane, di-i-butyldiethoxysilane,di-tert-butyldiethoxysilane, tert-butylmethyldiethoxysilane,tert-butylethyldiethoxysilane, tert-butyl-n-propyldiethoxysilane,tert-butyl-n-butyldiethoxysilane, tert-bamylmethyldiethoxysilane,tert-amylethyldiethoxysilane, tert-amyl-n-propyldiethoxysilane,tert-amyl-n-butyldiethoxysilane, dicyclopentyldiethoxysilane,dicyclohexyldiethoxysilane, cycohexylmethyldiethoxysilane,cyclohexylethyldethoxysilane, diphenyldiethoxysilane,phenylmethyldiethoxysilane and 2-norbornanemethyldiethoxysilane.

[0127] Polymerization of α-olefin

[0128] The “α-olefin” used in the present invention means that havingnot less than 3 carbon atoms. Examples of the α-olefin are straightchain monolefin such as propylene, butene-1, pentene-1, hexene-1,heptene-1, octene-1 and decene-1; branched chain monolefin such as3-methylbutene-1, 3-methylpentene-1 and 4-methylpenetene-1; andvinylcyclohexane. The α-olefin may be used each alone or in a mixture oftwo or more. Of these, it is preferred to use propylene or butene-1 eachalone, or a mixed olefin containing propylene or butene-1 as a maincomponent, and it is particularly preferred to use propylene alone or amixed olefin containing propylene as a main component.

[0129] In the present invention, it is permitted to use an olefinmixture of at least two members selected from the group consisting ofthe c-olefins mentioned above and ethylene. Further, it is permitted toadditionally use a compound having several unsaturated bonds such as aconjugated diene and a non-conjugated diene as a comonomer. With respectto a polymerization method, it is also possible to carry out ahetero-block copolymerization, in which the polymerization is carriedout not only at one stage but also at two or more stages.

[0130] The catalyst in accordance with the present invention can beobtained by contacting the aforementioned solid catalyst component,organoaluminum compound and electron donor compound (E2) with oneanother. How to contact them is not limited as far as the desiredcatalyst is obtained. With respect to a method for contacting them, forexample, the following methods (1) and (2) are enumerated. In carryingout the contact, the aforementioned respective components may be used asthey are, or may be diluted with a solvent.

[0131] (1) A mixture of the aforementioned three components is preparedto contact them.

[0132] (2) The aforementioned three components are separately suppliedto a polymerization zone to contact them in the zone.

[0133] In the method (2), it is permitted to first prepare a contactproduct by contacting any two components among three, and then supplythe contact product and the remaining one component to a polymerizationzone. With respect to a method for supplying respective components to apolymerization zone, it is recommendable to carry out the supply in aninert gas such as nitrogen and argon under water free conditions.

[0134] In the present invention, the α-olefin may be subjected topolymerization in the presence of the catalyst mentioned above, whichpolymerization is hereinafter referred to as “real polymerization”, orsubjected to pre-polymerization, followed by the real polymerization.Here, the “pre-polymerization” means polymerization of a small amount ofthe olefin in the presence of the aforementioned solid catalystcomponent and organoaluminum compound.

[0135] It is recommendable to carry out the pre-polymerization in aslurry state. As a solvent used for forming the slurry state, forexample, inert hydrocarbons such as propane, butane, isobutane, pentane,isopentane, hexane, heptane, octane, cyclohexane, benzene and tolueneare enumerated. It is allowed to use a liquid olefin in place of a partor whole of the solvent.

[0136] In the pre-polymerization, the organoaluminum compound is used inan amount of usually from 0.5 to 700 mol, preferably from 0.8 to 500mol, and particularly preferably from 1 to 200 mol per mol of thetitanium atom in the solid catalyst component.

[0137] An amount of the olefin to be pre-polymerized is usually from0.01 to 1000 g, preferably from 0.05 to 500 g, and particularlypreferably from 0.1 to 200 g per g of the solid catalyst component.

[0138] A concentration of the slurry in the pre-polymerization ispreferably from 1 to 500 g-solid catalyst component/liter-solvent, andparticularly preferably from 3 to 300 g-solid catalystcomponent/liter-solvent. A pre-polymerization temperature is preferablyfrom −20 to 100° C., and particularly preferably from 0 to 80° C. Apartial pressure of the olefin in the gas phase portion during thepre-polymerization is preferably from 0.01 to 20 kg/cm², andparticularly preferably from 0.1 to 10 kg/cm², but the olefin which isliquid at that pressure and temperature for the pre-polymerization isnot limited thereto. A time for the pre-polymerization is notparticularly limited, and it is usually preferably from 2 minutes to 15hours.

[0139] In the pre-polymerization, how to supply the solid catalystcomponent, the organoaluminum compound and the olefin is not limited.For example, the following methods (1) and (2) are enumerated. Here, itis permitted to use a chain transfer agent such as hydrogen in order toregulate a molecular weight of the polymer obtained.

[0140] (1) The solid catalyst component and the organoaluminum compoundare contacted with each other, and thereafter the olefin is supplied.

[0141] (2) The solid catalyst component and the olefin are contactedwith each other, and thereafter the organoaluminum compound is supplied.

[0142] Although how to supply the olefin is not limited, the followingmethods (1) and (2) are, for example, enumerated.

[0143] (1) The olefin is supplied one after another, while keeping aninternal pressure of a polymerization zone to a predetermined level.

[0144] (2) The whole amount of the olefin predetermined is supplied at atime.

[0145] If desired, a part or the whole amount of the electron donorcompound (E2) used for producing the catalyst as mentioned above may bepresent together in the pre-polymerization. The electron donor compoundis used in an amount of usually from 0.01 to 400 mol, preferably from0.02 to 200 mol, and particularly preferably from 0.03 to 100 mol permol of the titanium atom in the solid catalyst component, and usuallyfrom 0.003 to 5 mol, preferably from 0.005 to 3 mol, and particularlypreferably from 0.01 to 2 mol per mol of (ok?) the organoaluminumcompound.

[0146] How to supply the electron donor compound in thepre-polymerization is not particularly limited. It is permitted tosupply the electron donor compound independently from the organoaluminumcompound, or contact both in advance and then supply the resultingproduct.

[0147] The olefin used in the pre-polymerization may be the same as ordifferent from that used in the real polymerization.

[0148] In the real polymerization, the organoaluminum compound is usedin an amount of usually from 1 to 1000 mol, and particularly preferablyfrom 5 to 600 mol per mol of the titanium atom in the solid catalystcomponent.

[0149] In the real polymerization, the electron donor compound is usedin an amount of usually from 0.1 to 2000 mol, preferably from 0.3 to1000 mol. and particularly preferably from 0.5 to 800 mol per mol of thetitanium atom in the solid catalyst component, and usually from 0.001 to5 mol, preferably from 0.005 to 3 mol, and particularly preferably from0.01 to 1 mole per mol of (ok?) the organoaluminum compound.

[0150] A temperature of the real polymerization is usually from −30 to300° C., and preferably from 20 to 180° C. A polymerization pressure isnot particularly limited, and from an industrial and economical point ofview, it is usually from atmospheric pressure to 100 kg/cm², andpreferably from about 2 to 50 kg/cm². The polymerization may be carriedout in either a batch-wise manner or a continuous manner according to aslurry or solution polymerization method, wherein an inert hydrocarbonsolvent such as propane, butane, isobutane, pentane, hexane, heptane andoctane is used, or a bulk or gas phase polymerization method, wherein anolefin which is liquid at that polymerization temperature is used as amedium.

[0151] In the real polymerization, it is permitted to use a chaintransfer agent such as hydrogen in order to regulate a molecular weightof the polymer obtained.

EXAMPLE

[0152] The present invention is explained in more detail with referenceto the following Examples, which are only illustrative and not intendedto limit the scope of the present invention.

[0153] Physical properties of the polymer and compositions of the solidproduct and the solid catalyst were measured in the following manners.

[0154] 1. 20° C. Xylene-soluble Portion in Polymer (hereinafter noted asCXS (wt %))

[0155] CXS was measured according to the steps of:

[0156] (1) dissolving 1 g of the polymer in 200 ml of boiled xylene toobtain a solution,

[0157] (2) cooling gradually the solution to 50° C.,

[0158] (3) immersing the cooled solution in ice water under stirring,whereby the solution is cooled to 20° C.,

[0159] (4) continuing the cooling at 20° C. for 3 hours to precipitate apolymer,

[0160] (5) separating the precipitated polymer by filtration to obtain afiltrate, and

[0161] (6) weighing a polymer in the filtrate, which polymer is a 20° C.Xylene-soluble portion, to obtain the weight (W g) thereof.

[0162] A value calculated by 100×W is assigned to be CXS (wt %). Thesmaller the CXS value, the higher the stereospecificity of the polymer.

[0163] 2. Intrinsic Viscosity of Polymer (hereinafter noted as[η](dl/g))

[0164] Measured in a teralin solvent at 135° C.

[0165] 3. Bulk Density of Polymer (g/ml)

[0166] Measured according to JIS K-6721-1966.

[0167]4. Composition Analysis of Solid Product and Solid CatalystComponent

[0168] (1) Content of Titanium Atom

[0169] After decomposing a solid sample with diluted sulfuric acid, anexcess amount of a hydrogen peroxide aqueous solution was added thereto.A characteristic absorption at 410 nm of the obtained liquid sample wasmeasured with a double-beam spectrophotometer U-2001 manufactured byHitachi Co., Ltd. and then the content was found using the calibrationcurve prepared in advance.

[0170] (2) Content of Alkoxy Group

[0171] After decomposing a solid sample with water, an alcohol contentin the obtained liquid sample, which corresponded to the alkoxy group,was measured by an internal standard method of a gas chromatography, andthen converted into the alkoxy group content.

[0172] (3) Content of Carboxylic Acid Ester

[0173] After decomposing a solid sample with water, the obtained liquidsample was extracted with a saturated hydrocarbon such as n-heptane toobtain an extract containing materials soluble therein, and thecarboxilic acid ester content in the extract was measured by an internalstandard method of a gas chromatography.

Example 1

[0174] (1) Production of Solid Product

[0175] A 500 ml flask equipped with a stirrer and a dropping funnel waspurged with nitrogen, and thereafter 270 ml of hexane, 5.8 ml (21.9 mmolin terms of Ti atom) of tetrabutoxytitanium dimer, 2.5 ml (9.3 mmol) ofdi-i-butyl phthalate and 74 ml (329 mmol) of tetraethoxysilane were fedinto the flask to obtain a uniform solution.

[0176] Successively, 172 ml of a di-n-butyl ether solution ofn-butylmagnesium chloride (manufactured by Yuki Gosei Kogyo Co., Ltd.,n-butylmagnesium chloride concentration: 2.1 mmole/ml) was graduallyadded dropwise from the dropping funnel thereto over 3 hours whilemaintaining a temperature in the flask at 5° C. After completion of theaddition, the mixture was stirred at 5° C. for 30 minutes, andadditionally stirred for 1.5 hours at 35° C. Thereafter, the reactionmixture was cooled to room temperature, and subjected to solid-liquidseparation. The solid product separated was washed 3 times with each 200ml of toluene, and then mixed with 200 ml of toluene to obtain a slurryof the solid product having a slurry concentration of 0.149 g/ml.

[0177] After sampling a part of the slurry, a composition analysis wasconducted, and as a result, the solid product was found to contain 1.64wt % of the titanium atom, 0.07 wt % of the phthalic acid ester, 38.5 wt% of the ethoxy group and 3.63 wt % of the butoxy group.

[0178] (2) Production of Solid Catalyst Component

[0179] A 100 ml flask equipped with a stirrer, a dropping funnel and athermometer was purged with nitrogen. Thereafter, 54 ml of the solidproduct slurry obtained in the above (1) was fed into the flask, and 7.1ml of a supernatant liquid was taken out. The residue was stirred for 1hour at 105C, and cooled to 95° C. Then, 6.9 ml (25.8 mmol) ofdi-i-butyl phthalate was added thereto, and contact was effected at 95°C. for 30 minutes. Thereafter, the resulting solid was separated fromthe liquid at that temperature and washed two times with each 40 ml oftoluene at room temperature.

[0180] After completion of washing, 10 ml of toluene was added thereto.Further, a mixture of 0.8 ml (4.73 mmol) of butyl ether, 0.45 ml (1.68mmol) of di-i-butyl phthalate and 16 ml (0.146 mol) of titaniumtetrachloride was added thereto, and contact was effected at 105° C. for3 hours. Thereafter, the resulting solid was separated from the liquidat that temperature and washed two times with each 40 ml of toluene atthat temperature.

[0181] Successively, 10 ml of toluene and a mixture of 0.8 ml (4.73mmol) of butyl ether and 8 ml (0.0728 mol) of titanium tetrachloridewere added to the solid obtained above, and contact was effected at 105°C. for 1 hour. Then, the resulting solid was separated from the liquidat that temperature, washed three times with each 40 ml of toluene atthat temperature, additionally washed three times with each 40 ml ofhexane at room temperature, and then dried under reduced pressure toobtain 6.47 g of a solid catalyst component.

[0182] The solid catalyst component obtained was found to contain 1.70wt % of the titanium atom, 9.79 wt % of the phthalic acid ester, 0.08 wt% of the ethoxy group and 0.11 wt % of the butoxy group.

[0183] (3) Polymerization of Propylene

[0184] A 3 liter stirring type stainless steel made autoclave was purgedwith argon, and 2. 6 mmol of triethylaluminum, 0.26 mmol ofcyclohexylethyldimethoxysilane and 8.5 mg of the solid catalystcomponent obtained in the above (2) were fed in the autoclave, and thenhydrogen in an amount corresponding to a partial pressure of 0.33 kg/cm²Was introduced therein. Successively, 780 g of liquefied propylene wasfed therein and a temperature of the autoclave was raised to 80° C.Polymerization was carried out at 80° C. for 1 hour. After thepolymerization was over, the unreacted monomer was removed. Theresulting polymer was dried under reduced pressure at 60° C. for 2 hoursto obtain 328 g of a polypropylene powder. A yield of polypropylene perg of the solid catalyst component (hereinafter abbreviated as PP/cat)was found to be 38,590 (g/g), and a 20° C. xylene soluble portion (CXS)in the polymer, an intrinsic viscosity [η] of the polymer and a bulkdensity thereof were found to be 0.64 wt %, 2.18 dl/g and 0.371 g/ml,respectively. The results are as shown in Table 1.

Example 2

[0185] (1) Production of Solid Product

[0186] Example 1 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 4.9 ml (22.1 mmol in termsof titanium atom) of tetrabutoxytitanium tetramer.

[0187] The solid product was found to contain 1.40 wt % of the titaniumatom, 0.10 wt % of the phthalic acid ester, 38.5 wt % of the ethoxygroup and 3.42 wt % of the butoxy group. The slurry concentration was0.149 g/ml.

[0188] (2) Production of Solid Catalyst Component

[0189] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0190] The solid catalyst component was found to contain 1.61 wt % ofthe titanium atom, 11.1 wt % of the phthalic acid ester, 0.53 wt % ofthe ethoxy group and 0.08 wt % of the butoxy group.

[0191] (3) Polymerization of Propylene

[0192] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Comparative Example 1

[0193] (1) Production of Solid Product

[0194] Example 1 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 7.5 ml (22.0 mmol in termsof titanium atom) of tetrabutoxytitanium.

[0195] The solid product was found to contain 2. 11 wt % of the titaniumatom, 0.24 wt % of the phthalic acid ester, 39.3 wt % of the ethoxygroup and 3.15 wt % of the butoxy group. The slurry concentration was0.143 g/ml.

[0196] (2) Production of Solid Catalyst Component

[0197] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0198] The solid catalyst component was found to contain 2.04 wt % ofthe titanium atom, 13.8 wt % of the phthalic acid ester, 0.47 wt % ofthe ethoxy group and 0.08 wt % of the butoxy group. (3) Polymerizationof propylene

[0199] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 3

[0200] (1) Production of Solid Product

[0201] Example 1 (1) was repeated to obtain a solid product, except thatthe amount of di-i-butyl phthalate was changed to 5.0 ml (18.7 mmol).

[0202] The solid product was found to contain 1.61 wt % of the titaniumatom, 0.26 wt % of the phthalic acid ester, 34.9 wt % of the ethoxygroup and 3.24 wt % of the butoxy group. The slurry concentration was0.150 g/ml.

[0203] (2) Production of Solid Catalyst Component

[0204] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0205] The solid catalyst component was found to contain 1.61 wt % ofthe titanium atom, 12.0 wt % of the phthalic acid ester, 0.42 wt % ofthe ethoxy group and 0.12 wt % of the butoxy group. (3) Polymerizationof Propylene

[0206] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 4

[0207] (1) Production of Solid Product

[0208] Example 3 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 4.9 ml (22. 1 mmol in termsof titanium atom) of tetrabutoxytitanium tetramer.

[0209] The solid product was found to contain 1.39 wt % of the titaniumatom, 33.7 wt % of the ethoxy group, 3.08 wt % of the butoxy group andno phthalic acid ester. The slurry concentration was 0.134 g/ml.

[0210] (2) Production of Solid Catalyst Component

[0211] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0212] The solid catalyst component was found to contain 1.62 wt % ofthe titanium atom, 10.5 wt % of the phthalic acid ester, 0.46 wt % ofthe ethoxy group and 0.06 wt % of the butoxy group.

[0213] (3) Polymerization of Propylene

[0214] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Comparative Example 2

[0215] (1) Production of Solid Product

[0216] Example 3 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 7.5 ml (22.0 mmol in termsof titanium atom) of tetrabutoxytitanium.

[0217] The solid product was found to contain 1.78 wt % of the titaniumatom, 0.26 wt % of the phthalic acid ester, 36.1 wt % of the ethoxygroup and 2.94 wt % of the butoxy group. The slurry concentration was0.148 g/ml.

[0218] (2) Production of Solid Catalyst Component

[0219] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0220] The solid catalyst component was found to contain 1.96 wt % ofthe titanium atom, 14.6 wt % of the phthalic acid ester, 0.38 wt % ofthe ethoxy group and 0.06 wt % of the butoxy group.

[0221] (3) Polymerization of Propylene

[0222] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 5

[0223] (1) Production of Solid Product

[0224] Example 1 (1) was repeated to obtain a solid product, except thatthe amount of di-i-butyl phthalate was changed to 7.5 ml (28.0 mmol).

[0225] The solid product was found to contain 1.43 wt % of the titaniumatom, 0.2 wt % of the phthalic acid ester, 32.7 wt % of the ethoxy groupand 2.98 wt % of the butoxy group. The slurry concentration was 0.142g/ml.

[0226] (2) Production of Solid Catalyst Component

[0227] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0228] The solid catalyst component was found to contain 1.77 wt % ofthe titanium atom, 9.56 wt % of the phthalic acid ester, 0.45 wt of theethoxy group and 0.09 wt % of the butoxy group.

[0229] (3) Polymerization of Propylene

[0230] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 6

[0231] (1) Production of Solid Product

[0232] Example 5 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 4.9 ml (22. 1 mmol in termsof titanium atom) of tetrabutoxytitanium tetramer.

[0233] The solid product was found to contain 1.39 wt % of the E4titanium atom, 0.08 wt % of the phthalic acid ester, 32.0 wt % of theethoxy group and 2.88 wt % of the butoxy group. The slurry concentrationwas 0.140 g/ml.

[0234] (2) Production of Solid Catalyst Component

[0235] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0236] The solid catalyst component was found to contain 1.72 wt % ofthe titanium atom, 10.1 wt % of the phthalic acid ester, 0.43 wt % ofthe ethoxy group and 0.10 wt % of the butoxy group.

[0237] (3) Polymerization of Propylene

[0238] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (2) was used as thesolid catalyst component. The results are as shown in Table 1.

Comparative Example 3

[0239] (1) Production of Solid Product

[0240] Example 5 (1) was repeated to obtain a solid product, except thatthe tetrabutoxytitanium dimer was changed to 7.5 ml (22.0 mmol in termsof titanium atom) of tetrabutoxytitanium.

[0241] The solid product was found to contain 1.62 wt % of the titaniumatom, 0.42 wt % of the phthalic acid ester, 34.8 wt % of the ethoxygroup and 2.93 wt % of the butoxy group. The slurry concentration was0.145 g/ml.

[0242] (2) Production of Solid Catalyst Component

[0243] Example 1 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the above (1) was usedas the solid product slurry.

[0244] The solid catalyst component was found to contain 1.64 wt % ofthe titanium atom, 12.2 wt % of the phthalic acid ester, 0.38 wt % ofthe ethoxy group and 0.08 wt % of the butoxy group.

[0245] (3) Polymerization of Propylene

[0246] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above

[0247] (2) was used as the solid catalyst component. The results are asshown in Table 1.

Example 7

[0248] (1) Production of Solid Catalyst Component

[0249] A 100 ml flask equipped with a stirrer, a dropping funnel and athermometer was purged with nitrogen. Thereafter, 48.8 ml of the solidproduct slurry obtained in a manner similar to that of Example 1 (1) wasfed in the flask, and 22.3 ml of a supernatant liquid was taken out. Amixture of 0.8 ml (4.73 mmol) of butyl ether and 16 ml (0.146 mol) oftitanium tetrachloride, and successively 1.6 ml (11.1 mmol: 0.20ml/g-solid product)) of phthalic chloride were added to the residue,respectively. The resulting mixture was heated to 115° C., and stirredfor 3hours at that temperature. Thereafter, the resulting solid wasseparated from the liquid at that temperature and washed two times witheach 40 ml of toluene at that temperature.

[0250] After completion of washing, a mixture of 10 ml of toluene, 0.45ml (1.68 mmol)of di-i-butylphthalate, 0.8 ml (4.73 mmol) of butyl etherand 8 ml (0.073 mol) of titanium tetrachloride was added thereto, andcontact was effected at 115° C. for 1 hour. Thereafter, the resultingsolid was separated from the liquid at that temperature and washed twotimes with each 40 ml of toluene at that temperature.

[0251] Successively, 10 ml of toluene and a mixture of 0.8 ml (4.73mmol) of butyl ether and 8 ml (0.073 mol) of titanium tetrachloride wereadded to the solid obtained above, and contact was effected at 115% for1 hour. Then, the resulting solid was separated from the liquid at thattemperature, and washed three times with each 40 ml of toluene at thattemperature, additionally washed three times with each 40 ml of hexaneat room temperature, and then dried under reduced pressure to obtain6.12 g of a solid catalyst component.

[0252] The solid catalyst component was found to contain 1.93 wt % ofthe titanium atom, 9.12 wt % of the phthalic acid ester, 0.04 wt % ofthe ethoxy group and 0.19 wt % of the butoxy group.

[0253] (2) Polymerization of Propylene

[0254] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1.

Comparative Example 4

[0255] (1) Production of Solid Catalyst Component

[0256] Example 7 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the same manner as inComparative Example 1 (1) was used as the solid product slurry.

[0257] The solid catalyst component was found to contain 2.00 wt % ofthe titanium atom, 9.26 wt % of the phthalic acid ester, 0.04 wt % ofthe ethoxy group and 0.16 wt % of the butoxy group.

[0258] (2) Polymerization of Propylene

[0259] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 8

[0260] (1) Production of Solid Catalyst Component

[0261] Example 7 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the same manner as inExample 3 (1) was used as the solid product slurry.

[0262] The solid catalyst component was found to contain 1.97 wt % ofthe titanium atom, 9.00 wt % of the phthalic acid ester, 0.04 wt % ofthe ethoxy group and 0.20 wt % of the butoxy group.

[0263] (2) Polymerization of Propylene

[0264] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1.

Comparative Example 5

[0265] (1) Production of Solid Catalyst Component

[0266] Example 7 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the same manner as inComparative Example 2 (1) was used as the solid product slurry.

[0267] The solid catalyst component was found to contain 1.85 wt % ofthe titanium atom, 6.71 wt % of the phthalic acid ester, 0.03 wt % ofthe ethoxy group and 0.21 wt % of the butoxy group.

[0268] (2) Polymerization of Propylene

[0269] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 9

[0270] (1) Production of Solid Catalyst Component

[0271] Example 7 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the same manner as inExample 5 (1) was used as the solid product slurry.

[0272] The solid catalyst component was found to contain 1.84 wt % ofthe titanium atom, 7.71 wt % of the phthalic acid ester, 0.03 wt % ofthe ethoxy group and 0.18 wt % of the butoxy group.

[0273] (2) Polymerization of Propylene

[0274] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1.

Example 10

[0275] (1) Production of Solid Catalyst Component

[0276] Example 7 (2) was repeated to obtain a solid catalyst component,except that the solid product slurry obtained in the same manner as inExample 6 (1) was used as the solid product slurry.

[0277] The solid catalyst component was found to contain 1.83 wt % ofthe titanium atom, 6.24 wt % of the phthalic acid ester, 0.03 wt % ofthe ethoxy group and 0.13 wt % of the butoxy group.

[0278] (2) Polymerization of Propylene

[0279] Example 1 (3) was repeated to polymerize propylene, except thatthe solid catalyst component obtained in the above (1) was used as thesolid catalyst component. The results are as shown in Table 1. TABLE 1Polymerization activity CXS [η] Bulk density (g-PP/g-cat) (wt %) (dl/g)(g/ml) Example 1 38,590 0.64 2.18 0.371 Example 2 40,690 0.60 1.96 0.389Comparative Example 1 35,000 0.66 2.05 0.310 Example 3 47,120 0.65 2.040.392 Example 4 40,770 0.59 2.04 0.353 Comparative Example 2 26,560 0.741.94 0.326 Example 5 50,300 0.66 2.04 0.383 Example 6 51,940 0.82 1.970.384 Comparative Example 3 27,390 0.71 1.93 0.367 Example 7 53,950 0.442.17 0.430 Comparative Example 4 48,750 0.52 2.22 0.405 Example 8 66,6000.52 2.30 0.414 Comparative Example 5 52,120 0.52 2.14 0.422 Example 961,200 0.51 2.22 0.421 Example 10 56,350 0.40 2.40 0.406

1. A process for producing a solid catalyst component (1) for α-olefinpolymerization, which comprises the steps of: (1) reducing a titaniumcompound represented by the following formula [I] with anorganomagnesium compound in the presence of an organosilicon compoundhaving an Si—O bond, thereby obtaining a solid product, and (2)contacting the solid product with at least one member selected from thegroup consisting of an electron donor compound (E1) and an organic acidhalide, and a compound having a Ti-halogen bond, thereby obtaining thesolid catalyst component (1) for α-olefin polymerization,

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X² is a halogen atom or a hydrocarbyloxy grouphaving 1 to 20 carbon atoms, and all of X² may be the same or differentfrom one another.
 2. The process for producing a solid catalystcomponent (1) for α-olefin polymerization according to claim 1 , whereinthe step (2) comprises: (i) contacting the solid product with theelectron donor compound (E1) to obtain a contacted product, and (ii)contacting the contacted product obtained with the compound having aTi-halogen bond.
 3. The process for producing a solid catalyst component(1) for α-olefin polymerization according to claim 1 , wherein the step(2) comprises: (i) contacting the solid product with the compound havinga Ti-halogen bond and the organic acid halide to obtain a contactedproduct, and (ii) contacting the contacted product obtained with theelectron donor compound (E1) and the compound having a Ti-halogen bond.4. The process for producing a solid catalyst component (1) f orα-olefin polymerization according to claim 1 , wherein the electrondonor compound (E1) contains an organic acid ester or an ether.
 5. Theprocess for producing a solid catalyst component (1) for α-olefinpolymerization according to claim 1 , wherein “a” in the formula [I] is2 or
 4. 6. A process for producing a solid catalyst component (2) forα-olefin polymerization, which comprises the steps of: (1) reducing atitanium compound represented by the following formula [I] with anorganomagnesium compound in the presence of an organosilicon compoundhaving an Si—O bond and an ester compound, thereby obtaining a solidproduct, and (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining the solid catalyst component (2) for α-olefinpolymerization.

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X² is a halogen atom or a hydrocarbyloxy grouphaving 1 to 20 carbon atoms, and all of X² may be the same or differentfrom one another.
 7. The process for producing a solid catalystcomponent (2)f or α-olefin polymerization according to claim 6 , whereinthe step (2) comprises: (i) contacting the solid product with theelectron donor compound (E1) to obtain a contacted product, and (ii)contacting the contacted product obtained with the compound having aTi-halogen bond.
 8. The process for producing a solid catalyst component(2) for α-olefin polymerization according to claim 6 , wherein the step(2) coprises: (i) contacting the solid product with the compound havinga Ti-halogen bond and the organic acid halide to obtain a contactedproduct, and (ii) contacting the contacted product obtained with theelectron donor compound (E1) and the compound having a Ti-halogen bond.9. The process for producing a solid catalyst component (2) for α-olefinpolymerization according to claim 6 , wherein the electron donorcompound (E1) contains an organic acid ester or an ether.
 10. Theprocess for producing a solid catalyst component (2) for α-olefinpolymerization according to claim 6 , wherein “a” in the formula [I] is2 or
 4. 11. A process for producing a catalyst (1) for α-olefinpolymerization, which comprises the steps of: (1) reducing a titaniumcompound represented by the following formula [I] with anorganomagnesium compound in the presence of an organosilicon compoundhaving an Si—O bond, thereby obtaining a solid product, (2) contactingthe solid product with at least one member selected from the groupconsisting of an electron donor compound (E1) and an organic acidhalide, and a compound having a Ti-halogen bond, thereby obtaining asolid catalyst component (1) for α-olefin polymerization, and (3)contacting the solid catalyst component (1), an organoaluminum compoundand an electron donor compound (E2) with one another, thereby obtainingthe catalyst (1) for α-olefin polymerization.

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X²is a halogen atom or a hydrocarbyloxy grouphaving 1 to 20 carbon atoms, and all of X² may be the same or differentfrom one another.
 12. The process for producing a catalyst (1) forα-olefin polymerization according to claim 11 , wherein the electrondonor compound (E2) contains an alkoxysilicon compound represented bythe following formula, R³ _(r)—Si(OR⁴)_(4−r) wherein R³ is a hydrocarbongroup having I to 20 carbon atoms or a hydrogen atom, R⁴is a hydrocarbongroup having 1 to 20 carbon atoms, r is a number satisfying 0≦r<4, andall of R³and all of R⁴ may be the same or different from one another,respectively.
 13. A process for producing a catalyst (2) for α-olefinpolymerization, which comprises the steps of: (1) reducing a titaniumcompound represented by the following formula [I] with anorganomagnesium compound in the presence of an organosilicon compoundhaving an Si—O bond and an ester compound, thereby obtaining a solidproduct, (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (2) for α-olefinpolymerization, and (3) contacting the solid catalyst component (2), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining the catalyst (2) for α-olefin polymerization.

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X² is a halogen atom or a hydrocarbyloxy grouphaving 1 to 20 carbon atoms, and all of X² may be the same or differentfrom one another.
 14. The process for producing a catalyst (2) forα-olefin polymerization according to claim 13 , wherein the electrondonor compound (E2) contains an alkoxysilicon compound represented bythe following formula, R³ _(r)—Si(OR⁴)_(4−r) wherein R³is a hydrocarbongroup having 1 to 20 carbon atoms or a hydrogen atom, R⁴ is ahydrocarbon group having 1 to 20 carbon atoms, r is a number satisfying0≦r<4, and all of R³ and all of R⁴ may be the same or different from oneanother, respectively.
 15. A process for producing an α-olefin polymer,which comprises the steps of: (1) reducing a titanium compoundrepresented by the following formula [I] with an organomagnesiumcompound in the presence of an organosilicon compound having an Si—Obond compound, thereby obtaining a solid product, (2) contacting thesolid product with at least one member selected from the groupconsisting of an electron donor compound (E1) and an organic acidhalide, and a compound having a Ti-halogen bond, thereby obtaining asolid catalyst component (1) for α-olefin polymerization, (3) contactingthe solid catalyst component (1), an organoaluminum compound and anelectron donor compound (E2) with one another, thereby obtaining acatalyst (1) for α-olefin polymerization, and (4) subjecting an α-olefinto homopolymerization or copolymerization in the presence of thecatalyst (1).

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X² is a halogen atom or a hydrocarbyloxy groupand all of X² may be the same or different from one another.
 16. Aprocess for producing an α-olefin polymer, which comprises the steps of:(1) reducing a titanium compound represented by the following formula[I] with an organomagnesium compound in the presence of an organosiliconcompound having an Si—O bond and an ester compound, thereby obtaining asolid product, (2) contacting the solid product with at least one memberselected from the group consisting of an electron donor compound (E1)and an organic acid halide, and a compound having a Ti-halogen bond,thereby obtaining a solid catalyst component (2) for α-olefinpolymerization, (3) contacting the solid catalyst component (2), anorganoaluminum compound and an electron donor compound (E2) with oneanother, thereby obtaining a catalyst (2) for α-olefin polymerization,and (4) subjecting an α-olefin to homopolymerization or copolymerizationin the presence of the catalyst (2).

wherein “a” is a number of 2 to 20, R² is a hydrocarbon group having 1to 20 carbon atoms, and X² is a halogen atom or a hydrocarbyloxy groupand all of X² may be the same or different from one another.